Vanes for high speed tow cable



O United States Patent n 13,547,068

[ Inventor 7 2 [56] References Cited at Isa es, a l 1 pp. No. 807.227 UNITED STATES PATENTS 3 086 491 4/1963 Rather et al. ll4/235(.2F) [22] Filed March 14,1969 Cl k 4 1 5 5 Patented D 15 970 3,224,406 12/1965 ar ll /-3 A g Primary Examiner-Trygve M. Blix the United Sates of America, as represented Attorneys-Joseph C. Warfield, Jr., George J. Rubens, John by the Secretary of the Navy. by mesne W. Mc Laren and Truman L. Styner assignments ABSTRACT: The links of a cable for high speed towing comprises relatively stiff rods hinged end-to-end. Each link is faired or streamlined, in the direction of the swing of the hinge, so that the cable is relatively stiff laterally of the [54] g" Tow CABLE direction of travel, but quite flexible in the other direction. A aims ranwmg stabilizing hydrodynamic rudder is attached to each hinge, the [52] U.S.Cl 114/235 rudder comprising a lever arm attached at one end to the [51] Int. Cl B63b 21/00 hinge of the cable and having, at the other end, a flat planar [50] Field of Search 1 14/235, foil, or vane, substantially in the plane of travel of the cable to minimize kiting ofthe cable.

PATENfED DEC] 5 197B SHEET 1 BF 2 INVENTOR. MAX 0. KRA MEI? BACKGROUND OF THE INVENTION Cables to be towed in the water have long since been faired or streamlined in cross section to minimize drag as the cable is towed through the water. Hydrodynamics soon taught that the cross-sectional center of gravity ofcable must be well forward of the geometric center so as to give'dynamic control to the trailing edge and stability to the cable. Now, when the speed of the towing craft was increased to that of the hydroplane, a new phenomena has appeared. In spite of the most carefully hydrofoil design, the cable at the higher speed would tend to kite; that is, the cable would tend to plane or glide sideways and would actually come to the surface on either side of the path of the tow point. Worse, the cable would flip from one side to the other at some speeds and create a dangerous whipping action in the cable.

Accordingly, the principal object of this invention is to provide a cable which is stable in water at high speeds, and has minimum drag.

In solving the problem of the high speed cable, as disclosed in this invention, it was noted that the cable normally extends rearwardly from-the tow vessel in a downward catenary curve.

This means that different segments of the cable incline at different angles to the horizon. To stabilize all segments of the cable, from one end to the other, stabilizing rudders were attached at spaced intervals and were freely pivoted so as to trail easily regardless of the angle of attack of the cable in the water. Each stabilizing rudder comprises a vane with a long lever arm hinged at the forward end to the cable.

Other objects and features of this invention will become apparent to those skilled in the art by referringvto the specific embodiments disclosed in the following specification and shown in the accompanying drawings in which:'

' FIG. 1 shows, schematically, the towing cable and its normal catenary contour,

FIG. 2 is a perspective view, partly in section, of the tow cable of this invention,

FIGS. 3 and 6 show, in detail, one hinged joint of the tow cable of this invention,

FIG. 4 is a view, partly in section, of a winding drum for supporting the cable of this invention, and

FIG. 5 shows an exploded view of the hinge and vane of this invention.

The cable of this invention comprises a series of hinged, end-to-end links 10. The cable is norrnally'stowed on the reel 12 on the fantail of the towing ship. Underwater instrumentation, such as hydrophones, is enclosed in the streamlined, torpedo-shaped vessel 14. Where soundwaves are to be picked up, his important that the turbulence and noise of the cable moving through the water does not override the desired signals. The cable comprises a series of elongated, relatively stiff links. Since it is desired that the links not be stressed, the stowing reel 12, FIG. 4, preferably comprises a polygonal drum with sides adjusted in length to accommodate each link.

Preferably, each link comprises, as shown in FIG. 2, a leading edge or nose portion A of high-tensile strength stainless steel formed to, and molded with, the thin tailing piece of fairing 10B of plastic or other light weight material. The center of gravity of such a section is well forward'near the nose.

Multiple conductor cords 16 are imbedded preferably, in the plastic portion and within the protection of skirts of the metal nosepiece 10A.

One technique of construction is suggested in FIG. 5 where the steel nose portion 10A of each link is provided at opposite ends, respectively, with thesingle eye 11 and double eye 13.

Hinge pin l8 pivotly joins the interleaved eye 13. Hinge pin 18 pivotally joins the interleaved eyes of the links. Conveniently, the pins 18 may be extended some in length to receive the lever arm of a rudder, to be detailed below.

to protect the conductors 16 at the hinges, the fairings 10B are extended at the ends of the links into'the telescoping male and female clam-shell quadrants l5 and I7, res ectivel Specifically in FIG. 5, the arcuate member 1 pivoti y straddle the cable structure and is perforated to journal on the ends of pin 18. The thin planar vane 24, at the rear end of the lever arm 22, is in the plane of the hinged links l0 so that at high speeds the links are free to move in one plane only. With reasonably accurate manufacturing techniques, the foils 24 can make the cable follow in a fixed plane astern the centerline of the towing vessel.

Conveniently, the lever arm 22 and vane 24 can be made in two parts as shown in FIG. 5 and assembled over the ends of the pin 18 and fixed together as by rivetting or adhesives.

When the towing cable is reeled aboard, the links are laid in slots on the reel drum and the arms 22 folded into slots out of harm s way.

The length of the arm 22 and area of vanes 24 may be extended any desired amount to give the cable rotational stability at any water speed. It is clear that the pivoted rudders, with one degree of freedom can stabilize the cable and yet yield, as the angle of attack of the connected link changes, to permit the lever arm to level in the slipstream. Drag remains low at all speeds.

' Obviously, many modifications and variations of the present invention are possible in the light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

Iclaim:

l. The combination in a cable for high speed towing in water, said cable comprising;

a plurality end-to-end links, each link being elongated, and streamlined in cross section to facilitate lateral motion in water, adjacent ends of the links being so hinged as to permit free flexing of the cable in the plane of said mo tion,

a plurality of stabilizing hydrodynamic rudders, each rudder including a lever arm attached at one end to one of said links and having a planar vane at the other end, said lever arm and vane being so disposed as to fix said vane substantially in the wake of the connected link for minimizing kiting of said cable, and I said lever arm being pivotly attached to said link so that the angle of said link with the direction of the slipstream can change without changing the trailing position of said rudder.

2. In the cable defined in claim 1; the hinged ends of said links having complementary eyes engaged with a hinge pin.

3. In the cable defined in claim 2; the attachment of said lever arm to said link comprising means for pivoting said arm 65 on said hinge pin. 

